The present invention relates to a proximity detector of the inductive, capacitive, magnetic or photoelectric type which has remote dialogue facilities in order to enable an operator to carry out, notably, a detector learning function.
Some proximity detectors have a learning mode in order that the range of the detector can be automatically adapted with respect to the surroundings and/or with respect to a target. In fact, the inherent detection range of such an apparatus can vary from one detector to another, and for the same detector can vary according to the environment and assembly conditions, especially for an inductive detector embedded in solid metal. Furthermore, certain applications need the ability to change detector sensitivity according to its use. It is therefore useful to be able to make range learning for a proximity detector take place where it is used. Such a detector is notably described in document EP1143620.
Other proximity detectors are used to monitor rotation. In the same apparatus, they combine the conventional functions of detecting the presence of a target with the functions of counting the information received by the sensor over a given time, in order to compare, for example, with a preset triggering frequency on the apparatus in such a way as to output a signal which is the result of this comparison. In this way, we obtain an apparatus which is suitable for dealing in particular with problems of under-or over-speed with respect to a nominal frequency.
Document EP1130403 describes a detector for monitoring rotation, in front of which passes a target for which we want to monitor the frequency of passage compared to a normal frequency of passage. This detector has operator dialogue facilities consisting of a pushbutton and a dialogue electro-luminescent diode (LED) on the detector. The pushbutton serves to set the detector into a working mode or a learning mode. The learning mode enables the detector micro controller to calibrate the normal frequency of passage and makes it possible to select a detector operating margin about this normal frequency. In the learning mode, the dialogue LED associated with the pushbutton serves, for example, to guide the operator in setting the required detector operating margin.
However, as the size of a proximity detector is often very small, it is difficult to incorporate directly into the product those operator dialogue facilities needed to perform the learning functions. Furthermore, proximity detectors are often placed in an environment which is hostile for human beings, notably when close to moving machinery. Thus any operator manipulation of a pushbutton which is directly mounted on the detector would then be potentially dangerous.
The purpose of the present invention is to overcome these disadvantages by proposing a solution which makes simple installation of the dialogue facilities possible while also guaranteeing operator safety.